1. Field of the Invention
This invention relates generally to material handling apparatus and more particularly to a spiral chute for translating items from one level to another.
2. Description of Related Art
Declining chutes in the form of spirals is a component that is widely used in the material handling industry for conveying items from higher to lower elevations. Chutes are known to be fabricated from a variety of materials, including wood, metal, or plastics. In all cases, the chute is designed so that the items being handled will slide along a continuous conveying surface. Spiral chutes are generally known and are called spiral chutes because their edges and side walls form the shape of a spiral. Spiral chutes are specified by their degree of rotation, direction, width and inside radius. The degree of rotation, moreover, can be as large or as small as the particular application requires.
One such application comprises a system for air express parcel delivery. At the courier""s airport facility, parcels are consolidated into aircraft containers based on their delivery destinations. The operators loading the containers, however, can only load at a certain rate, and may be responsible for loading more than one container. It is therefore necessary to have an accumulation device for each container to serve as a buffer and to collect the arriving parcels while the container is unattended. This requirement dictates a relatively long chute such as a 540xc2x0 spiral having a constant inside radius so as to provide this functionality. Such a chute in effect forms a helix and has the advantage that it consumes less floor space than a straight chute.
Accordingly, it is an object of the present invention to provide an improvement in material handling systems.
It is a further object of the invention to provide an improvement in spiral chute delivery apparatus.
It is yet another object of the invention to provide a spiral chute configuration that eliminates the requirement for presorting, provides system redundancy and reduces the footprint of the system.
These and other objects are achieved by material handling apparatus which includes a pair of spiral chutes having the same inside radius which are nested one above the other about the same vertical axis. In a preferred embodiment, the two spiral chutes are mutually rotated such that their entry ports face in opposite directions, i.e. 180xc2x0, relative to one another. With the two chutes superimposed about the same vertical axis, a double helix spiral chute configuration is provided. Moreover, each chute has a dual entry capability by including both a top entry port and a side entry port downstream thereof that allows each chute to be served from two or more sources, while providing a respective single output port at the discharge end of the chute. With the chutes being mutually rotated 180xc2x0, the side entry port of one chute can be located adjacent the top entry port of the other chute so that a single sorting machine can feed both chutes. The same arrangement allows another sorting machine to feed both chutes on the opposite side Such a feature eliminates the requirement for presorting, and provides system redundancy in the event that a sorting machine for one source is out of service. The double helix, dual entry delivery chute configuration according to the subject invention provides a component with which to fabricate an improved material handling system.
Further scope of applicability of the present invention will become apparent from the detailed description provided hereinafter. However, it should be understood that the detailed description and specific example, while indicating the preferred embodiment of the invention, is provided by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.